1. Field of the Invention
The present invention relates to a navigation system and a navigation method that provides voice-guidance through a terminal device, such as a telephone, connected to a public circuit and able to transmit dual-tone multi-frequency (DTMF) signals, and also to a computer program product recorded on a recording medium containing the programs for executing the navigation processes.
This application is based on a patent application No. Hei 10-338269 filed in Japan, the content of which is incorporated herein by reference.
2. Description of the Related Art
It is sometimes difficult for a tourist arriving at a station near a destination to reach the actual intended spot, for example, when the traveler is not familiar with the local routes to the destination spot. A portable navigation system can provide aid in such a circumstance.
A portable device based on the global navigation system (GPS) is an example of such a portable navigation system. The GPS system utilizes wave signals transmitted from a satellite to obtain the present location and, by referencing the present location with the maps stored in the system, provides a navigation service to a desired destination.
However, although such portable GPS devices are becoming smaller with advances in technology, they do have certain weight and size, and it is bothersome for pedestrians including tourists to carry about such a bulky device.
Furthermore, batteries as power source are necessary part of any portable GPS devices, but as their capacity is diminished, GPS becomes inoperable.
An object of the present invention is to provide a navigation system that enables to guide a pedestrian to a destination location without having to use a portable device designed for navigation only.
The object has been achieved in a navigation system comprising: a memory section for storing location information for specifying a location, and longitudinal and latitudinal data relating longitudes and latitudes to a plurality of locations; a present spot locating section for obtaining a present location by receiving location information through a terminal device, connected to a public communication circuit, that can send dual-tone multi-frequency signals, searching through the longitudinal and latitudinal data, and obtaining longitudinal and latitudinal data on the present location; a destination spot locating section for obtaining a destination location by receiving location information through the terminal device transmitted by means of dual-tone multi-frequency signals, searching through the longitudinal and latitudinal data, and obtaining longitudinal and latitudinal data on the destination location; and a location computation section for computing at least one of either a distance or a direction between the present location and the destination location, and providing a voice report of computed results to the terminal device through the public communication circuit.
The present navigation system receives location information, related to the present location, entered by a user through a telephone device by means of dual-tone multi-frequency signals, obtains the longitudinal and latitudinal data, computes the distance and direction of move from the present location to the destination location, and reports the results by voice reports. Accordingly, the user (pedestrian) is able to find out the distance and direction to the destination location without having to carry a device intended only for navigation purposes.
Also the object has been achieved in a modification of the basic system comprised by: a memory section for storing location information for specifying a location, and longitudinal and latitudinal data relating longitudes and latitudes to a plurality of locations, and transport facilities data relating longitudes and latitudes to transport facilities; a present spot locating section for obtaining a present location by receiving location information through a terminal device, connected to a public communication circuit, that can send dual-tone multi-frequency signals, searching through the longitudinal and latitudinal data, and obtaining longitudinal and latitudinal data on the present location; a destination spot locating section for obtaining a destination location by receiving location information through the terminal device transmitted by means of dual-tone multi-frequency signals, searching through the longitudinal and latitudinal data, and obtaining longitudinal and latitudinal data on the destination location; and a transport means determining section for determining an optimal transport facility according to longitudinal and latitudinal data on the present location and on the destination location, in relation to the transport facilities data, and providing a voice report of determined routing to the terminal device through the public communication circuit.
The present navigation system receives location information, related to the present location and destination location, entered by a user through a telephone device by means of dual-tone multi-frequency signals, obtains longitudes and latitudes of the present and destination locations, determines a suitable transport facility according to the information obtained, and provides a voice report of the selected transport facility to the user. Accordingly, the user pedestrian) does not need to carry a device designed solely for the purpose of navigation, and is able to find a route to the destination location by using ubiquitous public phone systems